Automatic control of moving craft



Aug. 25, 1942 DE FLQREZ 2,293,889

. AUTOMATIC CONTROL. OF MOVING CRAFT Filed April 30, 1937 7 Sheets-Sheet 1 PUS/T/OIVAFTER b wt/gums ken/21V ALONG 7111s PATH 10/5 DE (20952 R INVENTOR Aug-25,1942 L. DE FLoR z 2,293,889

AUTOMATIC CONTROL OF MOVING C RAFT LUIS 0E FLQQEZ INVENTOR ATT RNEY Aug. 25, 1942. L. DE FLOREZ AUTOMATIC CONTROL OF MOVING CRAFT Filed April 30, 195'! 7 sneeis-sneei 4,

.I'A-i LU/5' of FZOREZ I III," vllllllvllllllyl j INVENTOR g- 25, 1942- L. DE FLOREZ 2,293,889

' I AUTQMATIFC CONTROL OF MOVING CRAFT Filed April :50, 1957 ,7 Sheets-Sheet 5 INVENTOR v A RNEY v Aug. 25, 1 942. D FLOREZ 7 2,293,889

AUTOMATIC CONTROL or MOVING CRAFT Filed April 50, 1937 7 Sheets-Sheet e 4015 DE Fmefiz INVENTOR Aug. 25, 1942. DE FLOREZ 2,293,889

AUTOMATIC CONTROL. OF MOVING CRAFT Filed April 30, 1937 7 Sheets-Sheet 7 V Z V ,u/xs 05 H0252 Y 1 mvzmon ',A ORNEY Patented Aug. 25, 1942 UNlTED' STATES PATENT OFFICE AUTOMATIC CONTROL OF MOVING CRAFT Luis de'Floi-ez, New York, N. 'Y., assignor to National Aviation Research Corporation, New York, N. Y., a corporation of Delaware Application April 30, 1937, Serial No. 139,868

21 Claims. (Cl. 244-18)" essarily depend upon the pilot to recognize or perceive the deviation and to then take the appropriate steps to effect the required control action. The effectiveness ofthe correction is thus dependent upon the attention'and skill of the pilot first in detecting the need for correction and in initiating the corrective measures with the required promptness and force to quickly arrest the change and start the craft back toward the true course and/or attitude, and to then ease off the control on approach to normal to just bring the craft back to the desired, course or attitude. A skillful and attentive pilot may thus quickly correct deviation without over-control and objectionable hunting eifects."

In so doing, the pilot takes into account andmakes allowance for the varying factors of rate of change, acceleration and extent-of deviation. Special objects of the present invention are to accomplish an equivalent-or even more effective control by wholly automatic means. 7

Automatic systems of control have been .proposed heretofore, but these whensufiiciently sensitive have had a tendency to over-control or create objectionable hunting. To overcome this, such systems have been in effect desensitized and made self-damping. This however, has had the eflect of rendering them somewhat sluggish in action, and in some instances has accentuated hunting.

Further objects of the present invention are to combine sensitive action with promptness and force of control and accurate return to the desired course or attitude.

In addition to the objects heretofore mentioned, it is a purpose of the invention to provide apparatus for accomplishment of the above, which will be simple, reliable, practical and efficient, relatively inexpensive and readily applicable to existing aircraft.

Further objects and the novel features of the invention are set forth or will appear in the course of the following specification.

The drawingsaccompanying and forming part of the specification illustrate certain practical 55 an embodiment of the invention embodiments of. the invention as applied to aircraft, but such illustration is primarily by way of disclosure and various modifications and changes may be made as will be apparent from the intent and broad scope of the cliaims.

Fig. 1 is a diagram. representing graphically the desired control effectfor bringing a craft back to course after an off-course disturbance. Fig. 2 is a diagram representing the factors of deviation, rate of change and acceleration necessary to be considered. 7

Fig. 3 is a diagrammatic picturization of course, turn indication and variable pressures exercised in checking an oil-course movement and bringing a craft back to the line of flight.

Fig. 4 is Ia. perspective, diagrammatic, broken and part sectional-view illustrating one embodiment of mechanism for combined steering and v aileron control of an airplane.

Fig. 5 isan enlarged broken vertical sectional detail of the diflfierential. air control valve actuated by the turn gyro, as-on line 5-5 of Fig.4.

Fig- 6 is a broken horizontal sectional detail of the difierential control valve operated 'by the acceleration detector, substantially as on line 6-5 of Fig. 4.

Fig. 7 is a broken sectional detail of the adjustable pick-up for aileron control as on substantially the, plane of line 1-1 of Fig. 4.

Fig. 8 is a schematic broken and part sectional view of a modified form of aileron control. p

Figs. 9 and 10 are broken sectional details of the automatic control valve employed as on lines 9-9, IO-HLofFig. 8. h

Fig. 11 is a broken perspective illustration oi for automatic control of pitchand climb. g s j 7 Figs. 12, 13, 14, 15 and 16 are similar views 01' modified forms of such control. v

In the present invention, instead of desensitizing to make the control self-damping, the sensitivity is retained so as to automatically and instantly detect any variations, and modifying influences are introduced to prevent oscillation or hunting. An ideal control eifect would be one such as represented in Fig. 1, where curve a, re-

sembling an asymtote represents the return ofthe craft to the original course after a disturb ation. In this curve, the maximum control is exerted at the beginning where the deviation is greatest and this is tapered off at a proper rate v to bring the craft back into the desired line of flight without hunt If control is effected only with reference to direction and extent of deviation, the course of 'a craft, as an airplane, may be such-as that represented by the curve A in Fig. 2, for simple "harmonic motion and the equation for which is:

where :n represents the angular deviation, t represents time and r and w are constants.

The curves B and C in this view representing respectively the rate of deviation and the change of rate or acceleration are derived from the equations dxldt=wr cos wt and To accomplish the effect illustrated in Fig. 1 therefore, it becomes necessary to coordinate the results 'of these three functions of deviation, rate of deviation and change of rate or acceleration and in the proper sign and magnitude.

In the present disclosure, the rate of deviation about any particular axis is determined -or detected by the rate of turn gyroscope and this is utilized to create or cause differential air pressures proportional to the rate of deviation. These differential air pressures are inturn caused to act upon a power cylinder, which effects cperation of the rudder in a direction to oppose the turning movement.

During such unbalancing of pressures, a pressure difference is built up in two integrating tanks, connected-with the power cylinder, which difference is proportional to the rate and time of the deviation. As the craft returns to its original course, the pressures in these integrating tanks become equalized. Thus during a disturbance and subsequent correction, the pressures in these integrating or so-called think The row of dials at the left shows the position of the rate of turn gyro and hence of the sensitive control .valve actuated thereby at different instants.

'In explanation, it may be considered that at point Pl, the craft is proceeding in the direction I of the arrow, the pressures are balanced in the power cylinder and integrating tanks, and the gym indicates no turn. At Pz'a disturbance has sent the craft into a right turn. the gyro shows right'turn and differential pressures of minus sign are started building up in the power cylinder'and integrating tanks with a corresponding movement of the rudder. Without the imme- "diate correcting efiect' of the power cylinder on ,the rudder, it maybe assumed that the craft would probably have deviated somewhat more, as along the broken line C...

During the whole period Pz-P: the craft is in a right turn and diflerential pressures (lines Cu and Co) continue building up in the power cylinder and integrating tanks.

At P: the turn of the craft has been fully arrested and at this instant, before a, left turn has begun, the gyro indicates no turn. To fully appreciate the subsequently explained operation,

it might be assumed for the instant, that the,

craft continued on a course tangent to P: as indicated by brokenline C77. The gyro would then continue to indicate zero, the control valve actuated thereby would be balanced and pressures in the power cylinder would tend to become "equalized along the broken curve indicated at C's. However, immediately the craft starts in its turn to the left fromcontinued influence of the rudder, the gyro shows left turn and the control valve positioned thereby strives to effect a reversal of sign in the diflerential of pressure in the air cylinder, thus accelerating reduction or collapse of the differential pressure. The broken curve C"b indicates thepath the pressure would follow if uninfluenced by the integrating tanks. The differential pressure of these'tanks as shown by curve Ce rose during the period Pr-Pa simultaneously with curve Cb, but'continued to rise, though at a reduced rate during P3--P4, while Cs was falling. At P4 the differential-pressure in the air cylinders and integrating tanks are equal-and immediately thereafter the curve Ce reverses direction and starts falling.

As a result, the slope of curve Cb is modified, falling in between curves C's and'C"b.

. During the period P4"Ps', the curves C Cb and Ce, each influenced by the others show the gyro and control valve returning to zero in smooth gradations, the left turn of the craft instituted to oflset the original disturbance becoming slower and slower and the pressures in the air cylinder and integrating tanks being gradually restored to balance. At P5 the disturbance has been compensated for and the craft has been brought back to the original line of flight or substantially so, after the pattern of the ideal control curve, Fig. 1.

In addition to this modifying effect for deviation, a modifying control for acceleration about any given axis, may be provided. This is accomplished in the present disclosure by a cylindrical mass mounted on frictionless hearings on the vertical axis of the craft and providing mechanical pressure proportional to acceleration for control purposes through diaphragms or'equivalent. w In the structural embodiment illustrated in Fig. 4, a precessional gyroscope is indicated at", having two degrees of'freedom and the gyroscopic force of which is proportional to the rate of deviation from agiven course. The precessional frame of this gyro is pivoted on a line 2|, corresponding to or parallel with the longitudinal axis of the craft and carries rpm 22, engagingin a forked lever arm 23, dependent from rock shaft 24, Journalled in casing 25, of a sensitive differential air control valve.

This valve is shown placed substantially vertically with the shaft substantially horizontal and the shaft is shown as carrying a generally cylindrical valve element 28, Fig. 5, operating freely in a cylindrical valve chamber 21, in valve and bottom ports 30, 3t and 32, 33, as well as with intermediate side ports 34, 35 in the valve casing. The upper pair. of ports 30, 32 lead 7 through control orifices or restrictions, such as 7 adjustable valves 41, 48. Other variable restrictions may be provided in these lines as indicated at 45, 50, and if desired, the two lines may be coupled by a valved cross connection, whichwhen further closedand pressure in line 55 and maphragm chamber 55 becomes nearer suction pressure while that in line 51 and chamber 55 becomes nearer atmospheric pressure. The differential of pressure acting on the diaphragms "in chambers and 55 produces a difi'erential me- .chanical pressure equal and opposite to the'force caused by the inertia, wheel 55. a

' Simultaneously the frame of the gyro 25' prethe valve is open will balance and hence in effect short circuit .the control valve to renderthe entire mechanism inoperative.

A second, sensitive differential control valve operable in response to acceleration of turning movement is indicated in Fig. 4, with the casing of the same at located horizontally and the shaft 52, arranged vertically and carrying at the lower end forked operating lever 53, engagedby pin 54, on the acceleration detecting inertia wheel 55, journalled on frictionless bearings on vertical axis 55.

The acceleration controlled valve, as indicated in Fig. 6, is similar in construction, but may be somewhat larger in size than the turn controlled valve. The side ports 34a, 55a, of this acceleration susceptible valve are shown connected by piping 51, 58, with opposite ends of a power cylinder 55, containing a piston fil'connected by a rod 5|, with rudder control bar 62; The upper or air inlet chamber 30a of the valve is shown equipped with an air filter 31a, and the lower, suction chamber 38a, is shown connected by piping 53-35 with venturi 45.

This one venturi thus provides power for the rudder operating air cylinder, modified and controlled by the two sensitive control valves, but while this is a desirable combination, it will be appreciated that suction pumps may be used or that with appropriate changes, positive pressure may be employed, supplied for example by Pitot.

are indicated branch lines 55, 51,.connected with diaphragm chambers 55, 55, similar and opposite to the diaphragm chambers 43, 44. The-diaphragms in the-opposite chambers are shown connected by rods ll, 12, and-these rods are hooked up with the acceleration wheel 55, by a cross lever 13, carried by or fixed to said wheel and having forked ends engaged between spaced collars 14, on the rods.

With the system in operation and the craft proceeding along the desired course, both sensitive control valves are in the neutral positions indicated in Figs. 4, 5 and 6, pressures are balanced and the rudder is held neutral. 1! there occurs a'disturbance causing the craft to turn to the right the inertia wheel 55 causes an initial relative rotation of the valve elements 25a in a counter-clockwise direction wherebyports 3|a and 32a are further opened and ports 55a and 35a cesses in a counter-clockwise direction moving.

valve' element also in the same direction. -.In so doing ports 5| and 52 are further opened and ports 55 and 53 further closedand pressure in line 4| becomes nearer suction pressurerwhile that in line 42 becomes nearer atmospheric pressure. 1 Y i I Due to the presence of integrating tanks 45 and 45 andthe adjustable restrictive'orificesfl and 45 and 45 and 55, the differential of'pressure in chambers 45 and 4 4 is not proportional to the rate of deviation but is modified by an amount proportional to'the amount of deviation, as 1'01- lows.- Flow of air along the lines 4| and 42 betweenthe rate controlled valve and chambers 45 and is restricted by orifices 45 and 55 and hence the pressure difference in 45' and 44 lags somewhat the pressure difference at the control valve. Likewiseduetoorifices 41 and 45 the pressure difference in'integr'ating tanks-45 and 45 lags somewhat that of the chambers 43 and the deviation. As the turn of the craft is ar-' rested after a disturbance but before it has been returned toits original course, there exists a differential pressure in thertanks 45 and 45,

while at this moment the rate controlled valve will be in the neutral position.v Now as the craft swings in the opposite direction to get back to the original course and the gyro swings 'accordingly, the flow of air through orifices "45 and is reversed and immediately following, thefiowthrough 41 and 45 is also reversedtend- I ing to maintain the diiferential pressure in chambers" and 44 until the craft has resumed its former course. v l t This diflferential pressure exerted on' diavphi-agms III in the chambers 45 and 44 produces a differential' mechanical pressure acting in the same directionas that produced by the inertia wheel 55 thereby still further opening ports 5|a and 52a and still further closingports 30a and 35a of the acceleration controlled valve and thus increasing the pressure, differential in chambers 55 and 55 by an amount suflicient to counterbalance this added force. l

Differential pressure equal to that of chambers 55 and 59 istransmitted to cylinder 55, and the rudder caused to 'move by an amount prbportional, to the combined efiect of l the deviation,

rate and acceleration.

, If the turn caused by the disturbance is one of constant angular deviation, the difierential- To avoid oscillation of the acceleration detectmovement of the plane. A further advantage is.

that with such a force, the manual controls may be used at any time to over-power and supersede the automatic control, without delaying to shut off the automatic control or to render it inoperative, as by fully opening .the valved bypass for connecting and balancing opposite sides of the system.

To permit the automatic system to take over full control of the rudder automatically when the pilot relinquishes such control, the arrangement shown in Fig. 4 may be employed. Here the rudder pedals indicated at 10, are connected with the rudder bar 19, by cables 00, which go slack from the tilting back of the pedals as soon as pressure is removed from such pedals. Thus whenever the pilot takes his feet 0115 the rudder pedals, the rudder is left free to be entirely controlled by the automatic system.

Where deviations from course are inclined to be abrupt or extreme, it mayat times be desirable to exercise corrective influence of the ailerons. For this purpose, there is shown in Figs. 4 and '1, a pickup connection between rudder andaileron actuating mechanism, comprising cables 8|, extending forwardly from the rudder operating bar 2, over pulleys 82, for actuating a rocker bar 88, pivoted on the main control shaft 84, and carrying adjustable screw abutments 85, to engage the opposite sides of a lever arm 80, secured on the control shaft by split clamp 81. When the lever element 86 is fixedly secured on the shaft by clamp 81, and the abutment screws 80, are properly adjusted, the movements of rocker 83, from the rudder control bar wiilhave the effect of rocking the control shaft and this through the lever arms 88 and linkage 88, will shift the ailerons 80, in proper direction and extent to aid the rudder in holding and bringing the ship back to course. By properly setting abutment screws 05, the aileron control can be cut into service for any desired movement of rudder and upon entirely retracting these screws or by loosening clamp 81, this supplementary aileron operation may be cut out of service.

Figs. 8, 9 and 10 illustrate an embodiment of the invention for maintaining proper lateral attitude in straight flight and proper banking angle in the turns. In this particular illustration, the control shaft 84, is rocked through leverage connections 9|, from a transversely disposed power cylinder 02, governed by a horizontal transversely positioned automatic control valve 80, having weighted diaphragms 94, 80, at the opposite ends of the same connected together at 80, and carry- 1 ing between them a sliding valve 81, having an intermediate valve head 88, controlling valve ports 88, I00,and end valve heads IOI, I02, controlling valve ports I00, I04. The intermediate valve ports 98, I00, are connected through annular chamber I00, with a suction line I00, and the end ports I03, I04,.connected by way of annular chambers I01, I08, Fig. 10, with a air inlet power cylinder inoperative.

passage I08, protected by an air fllter IIO. Ports III, II2, opening to the reduced portions III, II4, of the movable valve element are connected by piping I I0, IIO, with the opposite ends of power cylinder 82, and passages III, III, lead from such 13m; to the far or outer sides of the diaphragms Response control valves IIO, I20, are shown in the lines H0, H0, leading to the power cylinder and these two lines are shown connected by a by-pass line I2 I, provided with a valve I22, which may be partly or entirely opened to modify the action or completely balance and render the A control response valve is indicated at I28 in thesuctionline I00, for modifying the effect of the venturi 40, and this same line is shown provided with a valve I 24, for opening up the suction line to atmosphere time, ports I08 are closed or more nearly closed and ports I04 are more nearly opened to atmosphere. With this, increased suction is applied through passages II II I1 and reduced suction or approach to atmospheric pressure through passages II2II8, and the differential pressure on vthe diaphragms is suflicient to counterbalance the effect of gravity. This differential pressure transmitted to the power cylinder through lines IIS and H0 causes the rock shaft 84 to be turned anticlockwise and to raise the left and lower the irgigdht aileron to return the craft to a level atti- Incorrect banking which would cause skidding or "slipping" has a similar effect on the control valve 88. Thus during a right turn of insufficient bank, centrifugal force causes the diaphragm and sliding valve to move to the left and force to be applied by the power cylinder on the ailerons to bring the craft into proper bank.

In Fig. 11, proper longitudinal attitude is automatically maintained through a power cylinder I20, connected by a link and lever system I21, with the elevators I20. The forward end of this cylinder is connected 'by suction line I80, with a venturi 40a, which in this instance, serves the purpose of a vacuum pump and in'additlon, is utilized for speed sensitive purposes. The force created by this venturi is counterbalanced by spring I28, the strength of which is governed by regulation of bell crank I30, which can be secured at various adjustments at the quadrant I3I. With the proper adjustment once made, the ship will be automatically maintained on substantially level flight, for if the craft starts to nose down, the consequent increase in speed will exert increased-suction on the forward side of the piston to turn the elevators upward and if. the ship starts to nose up, with reduced suction,'the spring I28, will pull the elevators down to raise the tail, preventing stallin and thus keeping the ship in the proper longitudinal flying attitude.

If in this construction the automatic control is rendered inoperative 'as by opening valve I24, to cut out the power cylinder, the tension of is equalized in spring I29, may be correspondingly released at "I.

by the differential action of two power cylinders I26a, I25b, having their piston rods I32, I33, connected respectively at the end and to an intermediate portion of the elevator shifting lever I21. These cylinders are connected by branches I34, I35, with suction line I 08, the first of which has in it a restricting valve I36.

With increase of suction resulting from a diving angle, the lower cylinder I26b, will act first, thrusting outward of lever I21, with the connection I21, at the upper end of the lever moving slower or paus-v ing to serve as a floating fulcrum. A more or less sudden corrective movement is thus applied to the elevators and as suction becomes more effective in the upper cylinder I26a, this corrective movement is arrested and slowed down until the differential pressure as between the cylinders is equalized. In the return or opposite adjustment the first part of the corrective movement is more rapid and then again as pressure is eased 011 as the craft; is returned to the desired normal flying attitude.

Fig. 13 illustrates another modification of the Fig. 11 construction, in which operation of the Power cylinder I26, is governed from a sensitive control valve I38, similar to the turn controlled valve 25 in Fig. 4. The suction lines controlled by this valve are designated M a and 42a, and are shown connected directly with opposite ends of power cylinder I26. The action of this valve is effected by rocking the valve element through on the intermediate portion.

the two cylinders, the adjustment a projecting lever arm I39, connected by link I40, with a collapsible Sylphon bellows I4I, subiected through lin I42, to suction of venturi a.

In this construction, the Sylphon acts as-an amplifier to effect an immediate adjustment of e valve with relatively small changes in suction pressure resulting from increased or decreased speed from diving or climbing angles, easing oi the extent of such adjustment as corrections are efiected and the ship is returned tonormalflyingattitude. i

Fig. 14 illustrates a modification of the Fig.

- 13 construction similar to the differential action Fig. 12. In this case, there are two effected in Sylphons I4ia,, I4Ib, similar to the two cylinders I26a, I26b, Fig. 12, with the diiferential action of the same controlled by the restricting valve Ilia, which causes the Sylphon ID, to act first on the intermediate part of lever'I2Ia, which in this instance, acts through link I40, upon the sensitive control valve I38a, the diiferential Sylphon .I4Ia, carrying the floating fulcrum I 310, acting later by reason of restriction I36 a, to ease of! the control as the corrective adjustment is completed.

Fig. 15 illustrates how ,the'fore and aft control may be effected through a form of control similar to that utilized for lateral stability control shown in Fig. 8. In this case. the valve indicated at 93a, is placed longitudinally. so that detect and react to any in this case by subject movement of the piston and lifting of the ele-.- vators to bring the ship back into longitudinal with this construction, the automatic control is initiated immediately upon change in fore and aft attitude without waitin for the change in suction occasioned by increase or decrease in speedfollowing on the change inlongitudinal attitude. f f f The control valve is indicated as adjustable about an intermediate transverse mounting axis I43, being set at the proper fore and aft attitude by means of a positioning segment I44. Once secured in proper position, this valve will instantly change in longitudinal attitude and initiate the proper corrections to bring the ship back to the desired fore and aft flying position. .7 Z V Fig. 16 illustrates how the structure of Fig. 15 may be modified by,emp!oying aSylphon I4Ic'. similar to that indicatedin Fig. 13, for rocking the valve 9311, about its axis I43, to intensity or amplify theflrst portion of the corrective adjustment.

Also a differential control eifect is introduced the inner faces of the 7 two diaphragms to 'difierential pressure through lines I45, I46, the latter of which; has an interposed restrictive valve I41. These differential suction lines may be connected in the vent ports Ia, I46a, Fig, 10, and the two lines may be jointly connected with the suction'line I42, from the second venturi 40a, Fig. 16. An adjustable spring is indicated at I48, for balancing the valve against the Sylphon I 4Ic, so that in normal flight the valve element will occupy aneutral control position. a

In this Fig. 16 construction, the change from proper longitudinal position will effect operation of the valve from the action of the weighted diaphragms, increased throughtiltingof the valve from the Sylphon, which responds to change in suction through increase or decrease in speed resulting from the change in flying attitude. In addition, the differential pressure efe fected' on the dii'aphragms amplifies and then" eases off the controlling effect after the. manner of the floating fulcrum differential cylinders and diiferential Sylphons shown in Figs. 12 and 14..

Gages or indicators may be provided where it may be desirable, to provide. some indication of operation of the various parts. In particular, a gage of the differential type may be connected of! the differential pressure lines 51, 68, Fig. 4, sub

stantially as indicated at I49, which will indicate at all times the coordinated control effect of'the turn sensitive instrument, the acceleration con-' trolled device and the turn integrating means. The gyro or rate of turn instrument may be equipped with a suitable pointer or indicaton substantially as represented by the row of dials appearing at the left in Fig. 3.; 7 The various devices forJcontrolling direction of movement around one or more axes may be combined or be -used separatelyydepending; to some'extent on the degree of automatic control suitable to or desired dirigible craft. 1 V

Any desired degree of sensitivity may be 0b 7 tained so that, comparatively small movements of the change detecting instruments may be ampiifled to produce correspondingly greater move: ments in the actual control mechanism, as'for instance. by varyingthe leverage relations between for a particular form of the change sensitive instruments and the valves actuated thereby. The invention may readily be combined with the control mechanism of existing aircraft without interfering with the manual control or in turn being restricted or interfered with by such manual control. Thus as illustrated in Fig. 4, the automatic control mechanism does not interfere with manual operation of the controls which direct the craft and in its action is not required to operate the various controlling devices, such as the rudder pedals and the like, which otherwise might interfere with sensitivity of the apparatus.

To enable the pilot to make sudden rudder adjustments without first rendering the automatic control inoperative as by opening the differential pressure balancing'valve 65, the piston in the power cylinder may have oppositely acting spring closed relief valves therein, such as indicated at I50, ll, Fig. 4.

In Figs. 11, 12, 13, 14, 15,.and 16, the speed sensitive characteristic of venturis lliahas been used for control purposes. Other speed sensitive means, such as Pitot tubes may be used with appropriate changes in connections. Many other changes may be made to meet different conditions and requirements, all within the true spirit of the invention and the claims are to be read accordingly. 7

What is claimed is: r

1. In combination with dirigible craft provid-' ed with means for directing the same, power mechanism for actuating said directing means and means sensitive to turn of the craft, means for integrating the extent of turn and a separate device sensitive to acceleration, all connected to conjointly control operation of said power mechanism.

2. In combination with dirigible craft provided with means for directing the same, a turn sensitive instrument, an acceleration controlled instrument responsive to all values of acceleration, turn integrating means, connections between said three instrumentalities for modifying the effect of each by the others and power mechanism operable according to the conjoint efiect of the three instrumentalities and connected to control said directing means.

3. In combination with dirigible craft provided with directing means, a turn sensitive instrument, an inertia mass balanced for free move ment about the axis of turn, power mechanism for actuating said directing means and controlling connections from said turn sensitive means and inertia mass to said power mechanism.

4. In combination with dirigible craft provided with directing means, a turn sensitive instrument, an inertia massbalanced for free movement about the axis of turn, power mechanism for actuating said directing means, controlling connections from said turn sensitive means and inertia mass to said power mechanism and in-- cluding valves operable by said turn sensitive instrument and inertia mass respectively and pneumatic connections from said valves to said power mechanism. 7

5. In combination with dirigible craft provided with means for directing the same, a turn sensitive instrument, an acceleration controlled instrument, turn integrating means, connections between said three instrumentalities for modifying the effect of each by the others, power mechanism operable according to the conjoint effect of the three instrumentalities and connected to control said directing means and means for indicating the conjoint action of said three instrumentalities.

6. In combination with dirigible craft provided with directing means, power mechanism for actuating said directing means, turn sensitive means connected to exert a control over said power mechanism, turn integrating means connected to modify the control influence of said turn sensitive means in accordance with the extent of tum,-said turn sensitive means including a valve, diflerential pressure lines controlled thereby and said turn integrating means including differential pressure tanks connected with said differential lines and restricting oriflces'for timing the effect of said differential pressure tanks. I

7. In combination with dirigible craft provided with means for directing the same about a vertical axis, an acceleration controlled mass on the craft mounted for free movement about a vertical axis, power mechanism for actuating said directing means, controlling connections from said acceleration controlled mass to said power mechanism and turn sensitive means connected to modify t e control effect of said acceleration controlled mass.

8. In combination with dirigible craft provided with means for directing the same about a vertical axis, an acceleration controlled mass on the craft mounted for free movement about a vertical axis, power mechanism for actuating said directing means, controlling connections from said acceleration controlled mass to said power mechanism, turn sensitive means connected to modify the control effect of said acceleration controlled mass and turn integrating means connected to modify the control effect of both said turn sensitive means and said acceleration controlled mass.

9. In combination with a dirigible craft having a rudder, automatic means for operating said rudder and manual control means including rudder pedals movable to an inoperative position when pressure is removed therefrom and connections from said pedals constructed and arranged to slack ofi, when the pedals are in inoperative position, sufficiently to permit said automatic means to assume full control of the rudder.

10. In combination with aircraft having rudder and aileron control, automatic means for effecting the rudder control and adjustable pickup mechanism for effecting aileron control after a predetermined operation of said rudder control.

11. In combination with aircraft having rudder and aileron control, automatic means for effecting the rudder control and adjustable pickup mechanism for effecting aileron control after a predetermined operation of said rudder control and means for rendering said pickup mechanism effective or ineffective at will. I

12. In combination with aircraft provided with means for controlling lateral stability, a transversely disposed horizontally extending valve having connected weighted diaphragms and a valve body shifted laterally thereby in accordance with lateral deviations of the craft and differential pressure connections controlled by said valve body and arranged to exert a control effect over said lateral'stability controlling means. 7

13. In combination with aircraft provided with longitudinal stability controlling means, a longitudinally disposed valve on said craft and having connected weighted diaphragms and a valve body aaoaseo pressure connections controlled by said valve body and arranged to exert a controlling influence on said longitudinal stability controlling means.

14. In combination with aircraft provided with longitudinal stability controlling means, a longitudinally disposed valve on said craft and having connected weighted diaphragm and a valve body sshifted thereby in accordance with variations in longitudinal trim of the craft and differential pressure connections controlled by said valve body and arranged to exert a controlling influence on said longitudinal stability controlling means, said valve being mounted for tilting movement about a transverse axis and means for eflecting tilting adjustments of said valve about said axis.

15. In combination with dirigible craft provided with directing means, differential pressure power cylinders difierentially connected with said directing means and means for controlling operation of said diflferential power cylinders in accordance with deviation from predetermined flying attitude.

16. In combination with dirigible craft provided with directing means, power mechanism for controlling said directing means, differential pressure valve means for controlling said power mech-' mechanism and means sensitive to air speed for controlling said dlfl'erential pressure valve means.

18. In combination with aircraft provided with means for controlling the stability thereof about a desired axis, a valve having weighted diaphragms and a valve body shifted in accordance with deviations about said axis, and diflerential pressure means controlled by said valve for regulating said stability controlling means.

19. In combination a dirigible craft provided with means for controlling the same with respect to a particular axis, pneumatic power means con-' nected to actuate said control means, a venturi,

connections between said venturi and power means including a differential pressure control' valve and valve means between said venturi and difl'erential pressure control valve for opening said connections to atmosphere. V r

20. In combination with a dirigible craft provided with means for controlling'the same with respect to a particular axis, power mechanism including cooperative but independently acting devices for actuating said control means and speed responsive means connected with said cooperative but independently acting device and controlling same for automatically effecting first a rapid major adjustment of said control means and then a slower'reduced adjustment of said control means.

' 21. In combination with a dirigible craft provided with means for controlling the same in respect to a particular axis, power mechanism including cooperative but independently acting devices for effecting adjustment of said control means and means sensitive to air speed of said craft and connected with said cooperative independently acting devices for automatically effecting first a sudden major actuation of said power mechanism and then a slower lesser actua- 40 'tion of the same.

LUIS DI FLOREZ. 

